The NCP12711 is a fixed−frequency peak−current−mode PWM

controller containing all of the features necessary for implementing

single−ended power converter topologies. The device operates from

4 V to 45 V without auxiliary winding and within its thermal

capabilities. The controller contains a programmable oscillator

capable of operating from 100 kHz to 1 MHz and integrates slope

compensation to prevent subharmonic oscillations. The controller

includes a programmable soft−start, input voltage UVLO protection,

and an over−power protection (OPP) circuit which limits the total

power capability of the circuit as the input voltage increases. The

UVLO pin also features a shutdown comparator which allows for an

external signal to disable switching and brings the controller into a low

quiescent state. An onboard op−amp allows the implementation of

primary−side regulated converters or non−isolated dc−dc converters.

The NCP12711 contains a suite of protection features including

cycle−by−cycle peak−current limiting with smooth frequency increase

and a timer−based overload protection. All protection features place

the device into a low quiescent fault mode with a 1−s auto−recovery

period to allow for system recovery if the fault condition is removed.

Common General Features

• Wide Vcc Input Range (4 – 45 V)

• Internal 7.5−V Regulator

• Current−Mode Control with Adjustable Slope Compensation

• 0 Duty Ratio Operation in No−Load Condition

• Internal Over Power Protection

• Single Resistor Programmable Oscillator – 100 kHz to 1 MHz

• Adjustable Soft−Start on Peak Current and Frequency

• Programmable Input Voltage UVLO with Hysteresis

• Shutdown Threshold for External Disable

• Overload Protection with 30 ms Overload Timer

• Internal Operational Amplifier

• Fault Auto−recovery Mode with 1−s Auto−recovery Period

• ±1 A Source / Sink Gate Driver

Typical Applications

• Single−ended Flyback and Forward Converters for Electric Vehicles

• 4 − 45 V Input DC/DC Controller for Auxiliary Power